PipeMajor

My Feedback: (1)

We've (teenage son and I) been flying a kit-built Sig LT-40 as our first trainer. It now has about 50 flights on it and our skills have progressed such that I want to move the CG back from it's forward location to the middle recommendation. If I take the NiCD pack out from under the fuel tank and move it to the rear of the servos (leaving the Rx alone) I can shift the CG without any added ballast. I have a relatively heavy engine (ball bearing ABC .46 with stock muffler) so the LT-40 balanced pretty much out of the box.

Having it stuffed under the fuel tank floor was pretty easy since a wrap or two of ½" foam kept it in place. If you recall, the kit version of the LT-40 has large cutouts in the lite ply bottom, sides and top of the fuselage behind the wing. Not a lot of structure to play with.

I'd like to use velcro since I could fine tune the location but nothing there except the dull side of the MonoKote. I suppose I could glue in a cross member and mount the velcro or have like a ½" triangular or square stock at the seams and slot it for a velcro loop.

Any better ideas? Pictures would obviously be great.

j.duncker

My Feedback: (2)

Get some double sided servo mounting tape. [ Not the cheap stuff] http://www.sigmfg.com/IndexText/SIGSH119.html

Prepare the surface of the floor with a couple of coats of sealer.

Stick the battery to the floor using the tape. Works for me.

Ed Smith

Glue a ply plate in there and stick the velcro to it.

Ed S

TedMo

Both suggestions given above are plausible but my recomendation would be to obtain another plane that is designed for more aerobatic flight,if that's what you hope to achieve. Something with semi or full symetrical airfoil will permit inverted flight maneuvers etc. I'm not very familiar with the many high wing aircraft that may have such a wing but could recomend one that I know flies great and is available in several sizes; that being the Big Stik series. If you wish something more appealing one of the super Sportster, which is low wing are great.Fooling with CG placement it's not your best choice.

da Rock

You've got a good plan.

You will need to bridge those lightening holes. Any wood that looks solid enough to you probably will be. I used a couple of tongue depressors to carry an 800mAh NiCd at the rear of one model that is just now going into it's second year. Cut them to fit into the fuselage from side to side. Glued them at right angles to each other for strength and then into the fuselage. Two nights ago, I built a box in the back of a Tiger60 with 3/4" thick polystyrene wall insulation foam. Bridged it across the fuselage so it was supported by the liteply bottom and sides. Used canopy glue to hold it. Almost no weight.